changed display tooltip/link of attachments (front)

* image+name are now in 1 field
* tweaked css a bit
* removed references of el-
* tooltip of attachment includes name/file/description
added venue-attachments to event-view (front)

not sure why it was not there but when a venue has attachments and the
venue is shown at the venue page it does show the attachments of the
venue now to.